#include<stdio.h>
#include<math.h>
//make: gcc -o str str.c -lm
void main()
{
	printf("hello helen\n");
	int n=0;
	int count;
	int s_time;
	while(s_time !=160)
	{
		printf("----------hello, I am loop----------------\n");
		s_time=pow(2,n)*10;
		printf("s_time is %d\n",s_time);
		for(count=1;count<=n+1;count++)
		{
			printf("the %d times and sleep %d second\n",count,s_time);
			sleep(s_time);
			if(s_time==80)
			{
				printf("time is 80 now,need break!\n");
				break;
			}
		}
		n++;
		if(s_time > 5120)
		{
			printf("ooops ! break loop");
			break;
		}
	}

}

